Google has just pushed out more 3D buildings for Rome, Italy, and the result is a stunningly realistic 3D city. For a great example, here is St. Peter’s Basilica and Piazza in Vatican City:
You can also view historical landmarks such as the Colosseum, which is another amazingly detailed 3D model:
To see the buildings for yourself, simply search for “Rome, Italy” in Google Earth and make sure that you have the 3D Buildings layer turned on. You can also use this KML tour that Google has created to show off some of the best landmarks.